“Studying the biggest waves on Earth to understand our climate”

Among the 22 scientific projects carried out during the expedition, one focuses on waves. It aims at collecting an uninterrupted set of wind, wave, and surface current data throughout the entire expedition. Alessandro Toffoli, associate professor at the University of Melbourne and ocean wave expert, explains the project’s goals to Bastien Confino, embedded journalist, reporting for the Swiss radio and television (RTS).

– Alessandro Toffoli, why did you feel it was important to study waves here in the Southern Ocean?

As a result of climate change, temperatures are rising, winds are getting stronger, and, consequently, waves are getting bigger. This is especially true in the Southern Ocean, which already has the highest waves on the planet. When these waves hit the Antarctic ice sheet, they break up the ice and expose the underlying seawater to the sun’s rays, which makes the seawater heat up faster. If the ice disappears, it can no longer serve as the Earth’s refrigerator.

Exactly. Look at what’s happening during this storm. The waves are creating lots of tiny bubbles when they break. These bubbles are what enable the ocean to capture CO2, which then dissolves in the seawater. And the bigger the waves, the more CO2 is captured, making the ocean more acidic. Waves are a key interface between the ocean and the atmosphere. So understanding them better is crucial for the future of our climate.

If we can better understand the physics behind the waves in the Southern Ocean – the most complicated waves in the world – we can improve our models. That will reduce risks in the offshore oil and gas industry, help us build sturdier ships, and make ocean travel safer.

We use ships’ radars. Or more specifically, the “noise” from the radars. The ships’ navigation system picks out the radar signals that correspond to boats and icebergs, but throws out those corresponding to waves. We recuperate those signals to calculate the waves’ average height, direction, and frequency.